The Creation of Mouse Models for Human Diseases Associated with Reproductive Disturbances by In Vitro Fertilization and Embryo Transfer

摘要

The induction of ovulation by hormone treatment, preparation of fertilized eggs by in vitro fertilization and recovery of offspring by embryo transfer were studied in five strains of mutant mice: C57BL/6-dy/dy progressive muscular dystrophy model, C57BU6-ob/ob obesity model, and BALB/c-rl/rl, BALB/c- shi/shi and C57BL/6-mld/mld motor ataxia models. The homozygotes of these mutant mice are all affected with the disease about 2 weeks after birth, followed by reproductive disturbances. Ovulation could be induced by injection with PMSG-hCG in the females. Sperm was obtained from the cauda epididymis of males and used for in vitro fertilization. The success rate of the in vitro fertilization was as low as 71.6% in C57BL/6-dy/dy mice, but was over 85% in the other strains. When 2-cell embryos obtained by in vitro fertilization were transferred to the oviducts of pseudopregnant recipients, offspring were obtained from 39.2-57.7% of the transferred embryos. These offspring developed the expected diseases about 2 weeks after birth, and it was confirmed that the disease characters were reliably reproduced. These results demonstrate that the experimental system of in vitro fertilization and embryo transfer enables production of the offspring homozygous for a mutant gene and use of them for experiments before the onset of the disease which has been impossible.